If I were you I'd be seeking a second opinion.
I had a triple bypass in Oct 2009 and can honestly say it took me at least 12 months before I started feeling 'normal' again.
I think the meds had a lot to do with it - it takes time for the body to adjust to them.
As for the stent - if they can't get it in during an angio, surely if they put you under they can find a way to open up that blocked artery.
You really need to get a second or third opinion.